Carburetor



April 3, 1928.

C. E. WILLIAMS CARBURETOR Filed Dec. 8, 1920 Patented Apr 3, I928.

UNITED STATES "PATENT OFFICE;

CHARLES E. WILLIAMS, OF DETROIT, MICHIGAN, ASSIGNOR TO GENERAL MOTORS CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE.

CARBURETOR. I

Application filed December a, 1920. Serial no. 429,223.

This invention relates to carburetors and more particularly to carburetors of theauxiliary air valve type and has for one of its objects the .provision of thermally operated means for normally controlling the operation of'the auxiliary air valve so that the fuel mixture will be properly compensated to correspond to variationsin the temperature of the air supplied to the carburetor.

Another object of the invention is the provision of means for securing desired automatic compensation for varying atmospheric temperatures, in combination with the usual permanent and temporary manually operated adjustments for the air valve spring.

A still further object of the invention 1s the provision of means whereby the desired thermostatic compensation for variations of atmospheric temperature may be equally operativein its action of varying the tension on air valve spring in proportion to temperature variations by addition to or reduction of tension already brought about by operation of either of the manually operated adjustments.

Other and further objects and advanta es of the invention will appear as the-descrlption proceeds. I

On the drawings: a

Fig. 1. shows a side elevation of a carburetor, parts being shown in section and parts broken away, showing my improved .valve control in position thereon.

Fig.2 is a side elevation of that portion of the carburetor shown in Fig. 1 that extends laterally toward the right hand side of the drawing.

Fig. 3 is a view at right angles to that shown in Fig. 2 with parts in section.

Fig. 4 is a fragmentary view showing certain elements of the carburetor in perspective.

v The carburetor 1- is provided with the usual float chamber or bowl 2 havin the float 3 for controlling the flow of lquid fuel through .the inlet valve, not shown. A nozzle; 4 in communication with the float chamber at its lower end,extends into a strangle tube 5 which in turn is in communication with the mixing chamber 6 in which is located thethrottle "7; .The primary air enters the strangle tube and mixing chamber through the passage 8 about the nozzle 4. The parts thus far described are ,trols the and within the same, and to maintain at merely by way of example in order to illustrate how my invention may be applied. It is understood that my invention may be applied to forms of carburetors other than the one shown and described. The numeral 9 designates a lateral extension casing on the carburetor having an air passage 9' therein through which the secondary air is admitted to the'mixing chamber. The air is adapted to enter the passage 9 through the port or opening 10 which is .closed by any" suitable means as by means supply the proper amount" of air to said chamber under all thermal conditions about all times and under all temperature conditions the most eflicient and effective explosive mixture. v

In order to ensure the proper amount of air entering through the passage 9' to the mixing chamber to make the properexplosive mixture under all thermal conditions, I have provided the valve 11 withthermally controlled means for controlling the opening movement thereof. Y

Extending transversely through the outer end of the lateral extension!) is a rock-shaft 16 which carries a thermostat supporting member-17, said inember being clamped in place upon the shaft by means of screws 18 7- ow of air through the passage 9.

which extend through one end and into the body portion thereot,

A thermostatic arm or thermally controlled arm or member 19 is adapted to be secured to the member 17 in any suitable ture within the carburetor casing and about the same increases the arm will tend to straighten out thus relieving the. compression on the spring 20 and consequently renderingthe valve or closure 11 more easily operated. A set screw 23 extendmg through the extension casing 9 is adapted to engage the free end of the member 17 to thereby adjust the same, which adjustment ad usts the initial position of the element 19 and so con. trols the opposition of the spring 20 to opening movement of the valve 11. A detent 23 holds the screw 23 in adjusted position in the usual manner.

. A. suitable spring 30 may be employed to maintain the free end of the member 17 in contact with the set screw 23. As shown, this spring consists of a wire loop engaging the under side of the thermostat arm 19 adjacent to its end which is attached to the holdingmember 17 and having its ends bent to extend over the shaft 16 and to engage beneath the ledge 31. The arrangement described is such that the action of the spring 20 on the valve or clo-, sure 11 may be adjusted until the valvewill 0 en sufiiciently to permit the proper amount 0? air to be drawn into the mixing chamber to produce the proper mixture for any particular temperature conditions. After correct-adjustment has once been made by use of the set screw. 23, the thermally controlled arm 19 will. respond to temperature variations to automatically maintain the proper adjustment of the valve to insure correct mixture at all temperatures, thus doing away with the necessity for frequent seasonal readjustments usually required and insuring"- maximum efficiency of the engine at all times. A

* When it is desirable to temporarily enrich the mixture, as for starting the motor when it is cold, the usual manually operated mechanism for controlling the opening of the valve is provided. One form of this means is shown in Figs. 2 and 3. An arm or lever 24 is pivotally mounted on the rock-shaft 16 and has a lost motion. connection with said shaft and with the thermostat carrying memmeat/re ber 17 as by being provided with a lug or projection 25 (see Fig. 2) which engages between twospacedlugs 26 and 27 on a col-, lar 32 secured to the shaft 16. The lugs 26 and 27 are spaced apart suflicicntly to permit to a free limited movement of rotation of said member 17, and also to prevent displacement thereof in case of slight unintentional movement of the control rod or wire. A rod or Bowden wire 28 connected to the arm 24zand extending through the pivoted guide 29 extendsto an operating lever, not shown, within reach of the operator. It will thus be seen that the valve 11 may be manually operatedby means of the wire or 'rod 28 and arm 24 without interfering with the automatic function of the thermally controlled arm 19. In other words, when the manually controlled mechanism is employed, it co-opcrates with the thermally controlled means 55 in tensioning'the spring 20 to thereby control the operation of the valve 11.

In starting the engine, by manually operating the rod or Bowden wire 28, additional compression may be placed on the spring 20 W to hold the valve 11 closed to thereby enrich 1 the mixture. After the engine warms up the lever 21 may be moved to relieve the additional tension, and restore the valve to thermal control only. a

lit will thus be seen that by adjusting the screw 23, the proper compression may be put onthe spring 20, so that the engine suction will lift the valve 11 just sufficiently to permit theproper amount of air to pass into 1% the mixing'chamber to make the most ecient mixture under normal temperature conditions. Moreover, by means of'the manually operated devices the action of the spring may be adjusted to meet temporary thermal conditions.

The compensating action of thethermally controlled means accompanying every change of temperature, greatly reduces the usual warming up period of the motor in that the arm 19, while-it is cold, puts more pressure on the spring 20, thus tending to 'maintain the valve 11 closed and causing a richer f mixture to be delivered to the engine so that driving conditions are attained very soon after the motor starts. As the temperature within the carburetor casing rises the thermostatic arm 19 expands gradually relieving the pressure on-the air valve spring, thereby maintaining the mixture of fuel and air at the proper proportions throughout the entire range of movement of said arm. In other words, as the temperature at} the arm rises the action on the air valve spring is decreased to permit a greater volume of air to enter the mixing chamber, to make the proper explosive mixture, and vice versa.

It is thought from the foregoing taken in connection withthe accompanying drawings that the construction and operation of myj device will be' apparent to those skilled in the art, and that various changes in size, shape, and proportion and minor details of construction may be made Without depart- ,ing from the spirit andscope of the appended claims. i I (I What I claim is 1. In a device of the class described, a carburetor having an, air passage, a valve; for said passage, a, counterweight for said valve, a sprin for resisting the opening of; said valve, a t 'erniostatexposed to the temperature inside thebarburetor casing and operatively connected to said sprin for 'auto matically varying the resistance 0 the same, and mechanism associated-with said thermostat and acting through said spring for man'- ually controlling the openin of said valve, substantially asrshown and ascribed.

2. In a carburetor having a lateral extension provided with anopening thereinto, a hinged valve for said opening, a spring for resisting the, opening movement of said valve,

a rock-shaft secured in said extension, a clamp secured about said rock-shaft and having its free end extended, a thermostatic member extending aboutsaid rock-shaft and cluding a spring within the carsecured-to said clamp, and having its free end attached to said spring, and-means engaging the free end of said clamp ior adjust ing the tension of said spring, su stantially as shown and described. v

t '3. In a device of (the class described, a carburetor having a main air assage and" an auxiliary air passage, a wave for said auxiliary air, passage, controlling means, in-

buretor casing and i a thermally controlled arm associated'with said valve and acting through said spring for automaticall controlling the flow of air through sai auxiliary air passage said arm compensating for all temporary and seasonal variatlons of temperature, means for varying the tension of said spring and manually operated means acting through said spring for varying the resistance of said spring to meet temporary requirements of engine operation, substan- -tially as shown and described.

\ 4. In a carburetor having a main air pas "sage and an auxiliary'air passage, a valve for said auxiliar'y air passage, controlling means for said valve noludlng a thermostatic arl'nwithinthe carburetor casing for controlling the flow of air throughsaid auxiliary air passage, means for adjusting said arm, a lever having a lost motion connection with said controlling means, and manually operated means connected tosaid lever for controlling said valve independently of said controlling means, substantially as shown and described. e

o- 5. In a carburetor having an air passage, a valve for said passage, a spring secured to said valve to close the same, thermostatic means connected to said spring, a second spring acting upon said thermostatic means and tending to move the same in one direction, and means for adjusting said thermostatic means against the action of-said second spring, substantially as shown and described.

In testimony ,whereof I aflix my signature.

, 'cIfARLEs WILLIAMS. 

